Swimming Pool Safety Coping Element and Method of Manufacture Thereof

ABSTRACT

Swimming pool safety coping element and method of manufacture thereof The present invention relates to coping elements, in particular to coping elements used around the edge of a swimming pool. A swimming pool safety coping element ( 10 ) comprises an outer layer portion ( 12 ) and an infill portion ( 14 ), the outer layer portion at least partly bounding the infill portion. The coping element is manufactured by forming the outer layer portion from a Low Surface Energy material. A pressure sensitive adhesive ( 16 ) is then applied across a first surface of the outer layer portion. In a further step, a flowable polymer composition is poured onto the first surface of the outer layer, and allowed to set, to provide the infill portion.

The present invention relates to coping elements, in particular to coping elements used around the edge of a swimming pool.

Conventional coping elements installed around the edge of swimming pools are made from materials such as stone, concrete and reconstituted stone. Such coping stones are often formed with a bull nose or rounded exposed edge so that corners are eliminated from their profile in order to minimise the danger associated therewith. However, such coping elements remain hazardous, since if a user of the swimming pool was to slip or misjudge his entry into the water, he could collide with the coping stone and receive an injury, potentially a serious injury.

It is known from WO2009050426 to provide coping elements having multiple portions. WO2009050426 discloses an arrangement in which the different portions are provided with interlocking means, to allow them to be secured together. However, the provision of interlocking components (e.g. protrusions or depressions at the surface of a first portion for mating with a corresponding depression or protrusion provided on the surface of a second portion) is time-consuming and increases the cost of manufacture.

Thus, it is an aim of the present invention to provide an improved method for joining the different portions of a coping element.

Therefore, at its most general, the present invention may provide a method of manufacturing a swimming pool coping element in which an outer layer portion and an infill portion are joined using pressure sensitive adhesive.

In a first aspect, the present invention may provide a method of manufacturing a swimming pool safety coping element comprising an outer layer portion and an infill portion, the outer layer portion at least partly bounding the infill portion, the method comprising the steps of:

-   -   forming the outer layer portion from a Low Surface Energy         material;     -   applying a pressure sensitive adhesive across a first surface of         the outer layer portion; and subsequently     -   pouring a flowable polymer composition onto the first surface of         the outer layer; and     -   allowing the flowable polymer composition to set, to provide the         infill portion.

Effectively, the method of the first aspect of the invention provides a coping element having at least two portions: the outer layer portion effectively providing a skin, having e.g. non-slip properties, while the infill portion provides the bulk mechanical properties required by the application, e.g. resilience, so as to reduce the possibility of injury arising from any collision with the coping element.

By Low Surface Energy is meant a material having a surface energy below 30 dynes/cm (0.03 Nm), preferably below 25 dynes/cm (0.025 Nm), most preferably below 23 dynes/cm (0.023 Nm). The Low Surface Energy material may comprise at least one of the following compounds: silicone, ethylene vinyl acetate, and/or a block copolymer. A suitable block copolymer may be Evoprene™. Preferably, the Low Surface Energy material comprises heat-cured silicone rubber.

The outer layer portion may be formed through e.g. pressing, extrusion, or injection moulding. This may be followed by a curing step, at a temperature of e.g. 130-180° C. Additionally, materials having luminescent properties may be embedded in the outer layer portion. Suitable materials may comprise phosphors such as strontium aluminate or zinc sulphide. The luminescent material may help to define the edge of the swimming pool in conditions of low ambient light.

The provision of a Low Surface Energy material may help to ensure that the coping element is not easily wet by water e.g. from the swimming pool. Thus, by providing a coping element having a Low Surface Energy outer layer portion, it may be possible to reduce the risk of slippage on the coping element.

It has been found that Low Surface Energy materials are not easily bonded to other materials, e.g. materials typically used for the infill portion. Surprisingly, it has been found that this problem may be at least partly alleviated by applying pressure sensitive adhesive across a first surface of the outer layer portion, whereby this surface then receives the flowable polymer composition that provides the infill portion.

Preferably, the first surface of the outer layer portion is cleaned using an organic solvent, before the pressure sensitive adhesive is applied. Typically, this cleaning step is carried out using an organic solvent, such as an aromatic hydrocarbon. In a preferred example, the organic solvent may be xylene.

As is well-known in the art, a pressure sensitive adhesive is an adhesive that forms a bond when pressure is applied between the adhesive and a contacting surface. Typically, no solvent, water, or heat is needed to activate the adhesive.

The pressure sensitive adhesive generally comprises an elastomer mixed with a suitable tackifier. The elastomer may be e.g. silicone rubber. The tackifier may be e.g. a silicate resin.

The pressure sensitive adhesive may be applied e.g. by brushing, painting, or spraying.

Typically, the flowable polymer composition is prepared from at least one of the following materials: vegetable oil, urethane, epoxy, latex, block copolymer, polyethylene foam, and/or polypropylene foam. A suitable vegetable oil is castor oil.

In a preferred example of the method, the flowable polymer composition is prepared from castor oil and a further polyol as starting materials. In a particularly preferred example, the further polyol is a polyether polyol. It is also preferred that the further polyol is ethylene oxide tipped. The molecular weight of the further polyol is preferably at least 3000, more preferably at least 6000.

It is possible (although less preferred) that the further polyol is a polyester polyol. Furthermore, in less preferred examples, the further polyol may be tipped with a different alkylene oxide, for example, propylene oxide.

Generally, castor oil and/or the further polyol may be mixed with an isocyanate compound, resulting in a polyurethane blend that, on setting, may provide the infill portion. Effectively, the isocyanate compound may be considered to function as a hardener for the polyol mixture.

Typically, the polyol mixture comprises equal parts by weight of castor oil and the further polyol.

Typically, the infill portion comprises a filler, such as rubber crumb.

The step of allowing the polymer composition to set may be carried out at ambient temperature. Alternatively, higher temperatures may be used (e.g. 50-60° C.), to decrease setting time.

In a second aspect, the present invention may provide: a swimming pool safety coping element comprising an outer layer portion and an infill portion, the outer layer portion at least partly bounding the infill portion, wherein:

-   -   the outer layer portion comprises a Low Surface Energy material;     -   the infill portion comprises a polymer composition; and     -   a layer of pressure sensitive adhesive is provided between the         outer layer portion and the infill portion.

The outer layer portion, the infill portion, and the layer of pressure sensitive adhesive of the coping element according to the second aspect of the invention may comprise one or more preferred features of the corresponding elements of the first aspect of the invention.

The invention will now be described by way of example with reference to the following FIGURE in which:

FIG. 1 shows a cross-sectional view of a safety coping element according to an embodiment of the second aspect of the invention.

Referring to FIG. 1, a safety coping element 10 has a skin 12 that provides an outer layer portion and that partly bounds an infill portion 14. A layer of pressure sensitive adhesive (PSA) 16 is sandwiched between the skin 12 and the infill portion 14, thus bonding the skin 12 to the infill portion 14.

The skin 12 is prepared using silicone rubber, which is pressed and heat-cured to provide the shape shown in FIG. 1. Heat curing is carried out at a temperature of 130-180° C. The resultant heat-cured silicon portion has a surface energy of 22 dynes/cm (0.022 Nm).

The pressure sensitive adhesive 16 is polydimethylsiloxane rubber, mixed with a silicate resin tackifier.

The skin 12 is prepared for the application of the pressure sensitive adhesive by cleaning the surface to which the PSA is to be applied, using a xylene solvent. The solvent is then allowed to evaporate. After this stage, the PSA is painted on to the cleaned surface and allowed to rest until it becomes tacky.

After this, a flowable polymer composition is poured onto the PSA-coated surface of the skin 12, and allowed to set, to provide the infill portion 14.

The flowable polymer composition is made by blending the following components:

-   -   castor oil resin: 50 parts by weight;     -   6000 molecular weight ethylene oxide tipped polyether polyol         (Arco) 1374™): 50 parts by weight;     -   a suitable catalyzing agent, e.g. dibutyl tin dilaurate: 0.05         parts by weight; and     -   a rubber crumb filler (thermoplastic vulcanized rubber in RH31         cream colour, having a granule size of 1-4 mm): 150 parts by         weight

Optionally, 8 parts by weight of a molecular sieve may be added (e.g. zeolite) and 5 parts by weight TiO₂.

This blend is then mixed with an isocyanate polymer and allowed to react at ambient temperature and pressure, to provide a flowable polyurethane composition for pouring over the PSA-coated surface of the skin 12. The castor oil, the polyether polyol, and isocyanate polymer are mixed in stoichiometric amounts to provide a polyurethane blend, as is known in the art. For example, 21 parts by weight isocyanate polymer may be added to a blend comprising 50 parts by weight castor oil and 50 parts by weight of the polyether polyol. 

1. A method of manufacturing a swimming pool safety coping element comprising an outer layer portion and an infill portion, the outer layer portion at least partly bounding the infill portion, the method comprising the steps of: forming the outer layer portion from a Low Surface Energy material; applying a pressure sensitive adhesive across a first surface of the outer layer portion; and subsequently pouring a flowable polymer composition onto the first surface of the outer layer; and allowing the flowable polymer composition to set, to provide the infill portion.
 2. A method according to claim 1, wherein the Low Surface Energy material at least one of compound selected from the group consisting of silicone, ethylene vinyl acetate and a block copolymer.
 3. A method according to claim 2, wherein the Low Surface Energy material comprises heat-cured silicone.
 4. A method according to claim 1 or 2, comprising the further step, before the step of applying the pressure sensitive adhesive, of cleaning the first surface of the outer layer portion with an organic solvent.
 5. A method according to claim 4, wherein the organic solvent is an aromatic hydrocarbon.
 6. A method according to claim 5, wherein the organic solvent is xylene.
 7. A method according to claim 1 or 2, wherein the pressure sensitive adhesive comprises silicone rubber.
 8. A method according to claim 7, wherein the pressure sensitive adhesive further comprises a silicate resin.
 9. A method according to claim 1 or 2, wherein the flowable polymer composition is prepared using at least one of the following components: vegetable oil, urethane, epoxy, latex, block copolymer, polyethylene foam, and/or polypropylene foam.
 10. A method according to claim 9, wherein one of the starting materials in the preparation of the fiowable polymer composition is castor oil.
 11. A method according to claim 10, wherein one of the starting materials in the preparation of the fiowable polymer composition is a polyol other than castor oil.
 12. A method according to claim 11, wherein the polyol is a polyether polyol.
 13. A method according to claim 12, wherein the polyol is ethylene oxide tipped.
 14. A method according to claim 11, wherein the polyol has a molecular weight greater than
 3000. 15. A method according to claim 11, wherein the flowable polymer composition includes a filler.
 16. A method according to claim 15, wherein the filler comprises rubber crumb.
 17. A swimming pool safety coping element comprising an outer layer portion and an infill portion, the outer layer portion at least partly bounding the infill portion, wherein: the outer layer portion comprises a Low Surface Energy material; the infill portion comprises a polymer composition; and a layer of pressure sensitive adhesive is provided between the outer layer portion and the infill portion.
 18. A swimming pool safety coping element according to claim 17, wherein the Low Surface Energy material at least one compound selected from the group consisting of silicone, ethylene vinyl acetate and/or a block copolymer.
 19. A swimming pool safety coping element according to claim 18, wherein the Low Surface Energy material comprises heat-cured silicone.
 20. A swimming pool safety coping element according to claim 17 or
 18. wherein the pressure sensitive adhesive comprises silicone rubber.
 21. A swimming pool safety coping element according to claim 20, wherein the pressure sensitive adhesive further comprises a silicate resin.
 22. A swimming pool safety coping element according to claim 17 or 18, wherein the flowable polymer composition comprises at least one of the following components: vegetable oil, urethane, epoxy, latex, block copolymer, polyethylene foam, and/or polypropylene foam.
 23. A swimming pool safety coping element according to claim 17 or 18, wherein the flowable polymer composition includes a filler.
 24. A swimming pool safety coping element according to claim 23, wherein the filler comprises rubber crumb. 